how to fix P0301 code in Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before starting the repair.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unscrewing the retaining bolts and unplugging the electrical connector.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for wear or deposits; replace with an OEM equivalent if necessary.
• Torque the new spark plug to the manufacturer's specification (typically 13-15 lb-ft).

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, inspect the ignition coil for cracks or damage.
• Replace the ignition coil if necessary, ensuring it is seated properly on the spark plug.
• Reconnect the electrical connector and secure the coil with the retaining bolts.

4. Check Fuel Injector

• If misfire persists, remove the fuel injector from cylinder 1 using a fuel injector puller if necessary.
• Inspect the injector for clogs or damage. Clean or replace the injector as needed.
• Reinstall the injector, ensuring it is seated correctly and connected properly.

5. Clear Codes and Test Drive

• Reconnect the battery terminal.
• Use the OBD-II scanner to clear the P0301 code.
• Start the engine and perform a test drive to confirm the issue is resolved.